A massive fire that recently tore through a Brooklyn warehouse destroyed documents from more than 1 million court cases, a New York state court official said Tuesday.

The fire on Jan. 31 ruined about 85,000 boxes of case files, said Ron Younkins, the state Office of Court Administration’s executive director. Some of them predate the Civil War, while others were as recent as 2011, he said, adding that all the cases were closed.

The city has been threatened with at least one lawsuit stemming from the fire. Personal injury attorney Robert Vilensky said in court papers last month that he lost nearly 800 boxes of files he had stored in the warehouse. He claims the city’s fire department may have been negligent in prematurely turning off the building’s sprinkler system.

Vilensky said Tuesday that he also planned to file suit on behalf of other law firms who lost records, although he would not name them. He said lawyers were concerned about being sued by clients, since they are obligated to keep records for certain amounts of time.

The court records that were lost came from state Supreme Court and family courts in all five New York City boroughs.

Three New York City agencies also lost documents in the blaze, along with health companies and law and financial firms, according to Recall Holdings, the parent company of the building’s owner.

Requests for files that were destroyed will be handled on a case-by-case basis, Younkins said. Some documents were created in duplicate, he said, and others can be accessed digitally or on microfilm.